I have seen incidents where a man might be AWOL for lengthy periods, later declared as a deserter, only to subsequently reappear.

Muster records for many units during the last year and half of the war were lost, destroyed, etc. in the sacking of Richmond. In these
cases, we have no evidence of men returning which we know through other sources actually took place.

For instance, my ggrandfather's 43rd Tennessee, following their surrender at Vicksburg, July 4, 1863, only one muster roll survives, that
dated March 10/11, 1864 of which only seven of the ten companies appear. Yet they served until May 5, 1865 serving as Cavalry escort
to Jefferson Davis.